Chair.



E. s. WATKINS CHAIR.

APPLICATION FILED JUNE 12, 19l3.

Patented June 25, 1918.

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x v ,Be itiknown thatI, Enwn nn ,G. WATKINS,

a citizen nf the i United. S il l ie residing at a d??? i i r 1 f i 9 Wo ste fi Commonwealth of Massachusetts, 1 l have. n-

vented a ,new and useful Improvementllin Chairs, .l,of which the following, together with the aecon panyingdrawing, is a specification. I

.Myinvention relates to. chairs andmore particularly to revolving ,chairs so; constructed as .to be vertically adjustable at will. The objectoftheinventionis to provide anim proved form of connection between the seat and baseof a chair whichwill permit the seat to .revolvewith .resp ect to the base and to be. vertically, adjusted to and from the base, theconstruction including means for, locking the parts against accidental change ,in vertical. adjustment without interfering with the rotation of the seat.

ance with my invention; Fig. 2 is a plan View on the linev 2 21 ofFigl l, the free eX- tremities of the legs of the chair being broken away Fig.. 3 is a. side. view v.ofythe adjustable connection Fig 4 is a view similar to Fig. 3; but with partsshownin section to show details of construction; and Fig. 5 is a view similar tmthcilowmqportion of Fig. 4, but with the locking'member in its inoperativ .pes ticm Like reference characters refer tosimilar parts in the different figures.

In the form of the invention shown in the drawing the chair includes a seat 1 which supports a back 2 and arms 3. Secured to the lower surface of the seat is a seat iron 4 having a downwardly extending projection 5, there being a tapered opening 6 extending vertically through the iron at the center of its projection. The tapered upper end of the threaded spindle 7 fits into the tapered opening 6, the friction between the two parts being sufficient to hold them in firm engagement, or, if desired, the upper end of the spindle may be headed over to guard further against separation of these parts.

The legs 8 of the chair are joined together by a spider 9 to form a supporting base. A

Specification of Letters Patent. 7. Appii eati on filed J'u ne l2, 1913. serj lal No. 773,19'3.

atented J une. 125, 1918.,

out and finishingthe bore 10, the. is

preferablycast with open spaces 11 concentric with and larger than the boreitself.

The bore 10 being smooth, there is nothing in the bore itself to'prevent verticalinovementofthespindle 7therein. To support the spindle 7. the nut 12"is provided. This nut is threaded. onto the spindle and is pro-, vided with an annular projection 13 on its under face fitting into an annular seat 14 on top of the spider, the projection 13 ofthe nut and the seat 14 of the spider being concentric with the axes of the nut 12 and the bore 10 respectively. The seat 14 is concave in cross sectionso as toform a reservoir or retention cha n ber for lubricant, such as hard grease, graphite or the like and the annular projection l3iseonve2; so as to turn properly on ,its lubricated seat. This construction, therefore,' provides a bearing whiclr nay be lubricated so as to prevent the squeaking which has been found objec- ,tionabl'e in previous devices of this character. Oneside of theupp'er. face of the; nut l2'is provided witha narrow slot '15 and Q t pivot .1 ext di ns erse across this slot, is mounted the locking member 17. The spindle 7 is provided with alongitudinal slot 18 to receive one edge of the locking member 17 when the locking member is in its upper position as shown in Figs. 1, 3 and 4. The locking member 17 when in this position serves to prevent relative rotation of the spindle 7 and the nut 12. The nut, however, is free to rotate upon the seat 14 as the spindle 7 is turned in the bore 10. It is thus clear that the chair seat may be revolved as much as desired without any danger of variation or change in its vertical adjustment with relation to the base of the chair. When it is desired to raise or lower the seat of the chair or, in other words, to change its vertical adjustment with relation to the base of the chair, the locking member 17 is would be'great enough to cause. the nut to rotate upon its seat 14: with the spindle so as to prevent vertical motion of the spindle. The stud, or stop 19, preferably integral with the spider 9, is therefore provided. This's'top projects upwardly into the path of the projection upon the locking member-'17 when the locking member is in its inoperative position as shown in Fig. 5. Under such conditions the nut 12 may rotate 'upon its seat with the spindle until the projection 20 hits the upper end of the stud 19. Further rotation of the stud is then impossible, the spindle 7 then turning in the nut'so as to move upwardly or downwardly as desired. The locking member 17' is held in either its operative or inopera- I tive position by the spring pressed pin 2].

which engages the projection 22 of the looking member upon one side or the other according to the position of the locking member as shown in Figs. 4: and 5.

' It is very probable that after having adjusted the chair tothe desired height in the manner which has been described, the groove or slot 18 will not lie exactly opposite the locking member 17 so as to receive the locking member when it is thrown upwardly against the spindle. Under such conditions the edge of the locking member will strike against the spindle and will be held in this position by the spring pressed pin- 21 until, at some later time, the spindle becomes turned so as to bring the slot 18 opposite the locking member. The pressure of the spring pressed pin 21 will then serve to complete the upward movement of the locking member 17 so that it will drop to the bottom of the groove and lock the nut and spindle securely together. The screw 23 supported in the stud 19 projects over the edge of the nut 12 so that the spindle and nut cannot be lifted from the base of the chair when the chair is picked up to carry it from place to place.

The spindle is provided with a transverse pin 24 near its upper end, this pin serving as a stop to prevent the projection 5 of the seat iron 4 from coming into contact with the upper end of the nut 12 so as to loosen the seat from the spindle.

While I have shown and described the details of one form of my invention, I do not wish to be limited to such details as changes may be made within the scope of the appended claim without departing from the spirit of the invention; but having described my invention, what I claim as new and desire to secure by Letters Patent is:

In a revolving chair, the combination with a spider having a vertical bore, and providing an annular concave seat surrounding the upper end of said bore, of a threaded spindle turning loosely in said bore, a chair seat on the upper end of said spindle, and a nut threaded on said spindle, said nut having a convex under surface corresponding to the outer circumferential portion of said annular concave seat, and 15 adapted to be supported by the latter to carry the weight of the chair seat, said nut being recessed inwardly of said convex surface, whereby to cooperate with the inner circumferential portion of said concave seat in forming an annular space, surrounding said spindle for the retention of lubricant.

Dated this fifth day of June 1913.

EDWARD Gr. WATKINS.

Witnesses:

CHAmins A. BROWN,

FLORENCE L. Moore.

Gopies' of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

" Washington, D. 0. 

